The overall objective of this part of the project is to develop agents that might be applied to achieve a selective inhibition of follicle stimulating hormone (FSH). Two different approaches will constitute the investigation, with an emphasis on isolation and purification. Inhibin, which is a protein implicated in control of FSH secretion, will be isolated in purified form from bovine seminal plasma, using ethanol precipitation and column chromatography. Further purification is achieved by affinity column chromatography and preparative iso-electrofocusing. Preliminary purification of inhibin has been achieved and a bioassay using castrated male rats has been set up. A detailed physicochemical characterization of this protein will be undertaken. These include electrophoretic properties, molecular weight, chemical composition, end group analysis, biophysical characteristics and homogeneity studies. Our aim is to determine its amino-acid sequence. A radioimmunoassay for bovine inhibin will be developed and inter-species cross-reaction will be investigated. If cross-reaction permits, inhibin levels in the male rat at various ages will be measured. FSH will be isolated from frozen sheep pituitaries and its beta subunit will be prepared in highly purified form. The methods to be used have been published by us and well standardized in our laboratory. The beta subunit of FSH will be used by Dr. Madhwa Raj for active immunization of monkeys.